Advice on loading a boat on the trailer

Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
Would anyone have an opinion on where the balance point on this boat would be?
I have it on a lake that doesn't have a travel lift so I'll have to put it on a trailer directly from the water. On my first attempt, I lined up the center of the keel with the center axle (of a three axle trailer) but that was too far back and disaster ensued. I realize it will still be trial and error to get the tongue weight correct, I am just trying to plan ahead to minimize the time spent tying up the launch ramp.
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Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
Not sure exactly what disaster could have resulted from that... I hope no one was injured and the boat was not damaged. If you lined up the keep with the center axle of a 3 axle trailer, it was firmly seated on a keel pad, and the bunks were set properly the only thing that I can imagine is that the boat still tipped the trailer backward; this means that all three axles are set too far forward on the trailer. You want the center of gravity to rest at a point forward of the trailer's center axle so you get effective tongue weight. People try to set sailboats too far back on trailers because they are worried about overall tongue length and splashing the hull deep enough to avoid swamping the tow vehicle. Setting up a trailer for a particular boat is critical.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
Not sure exactly what disaster could have resulted from that... I hope no one was injured and the boat was not damaged. If you lined up the keep with the center axle of a 3 axle trailer, it was firmly seated on a keel pad, and the bunks were set properly the only thing that I can imagine is that the boat still tipped the trailer backward; this means that all three axles are set too far forward on the trailer. You want the center of gravity to rest at a point forward of the trailer's center axle so you get effective tongue weight. People try to set sailboats too far back on trailers because they are worried about overall tongue length and splashing the hull deep enough to avoid swamping the tow vehicle. Setting up a trailer for a particular boat is critical.
Yes, the boat was too far back on the trailer so when we tried to pull forward, the tongue raised way up and the boat slid backwards; until it rested on the rudder. No one was hurt and the boat doesn't appear damaged. We motored it back to the slip and all appeared fine. (a closer inspection will occur when we do get it out of the water) What I am asking for is someone with more experience loading trailers to give me a better guess as to where the center of gravity on this particular boat would be. It is a 30' Goman Express.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Cowpoke.
Sorry to here your challenge. It is one of the many issues that comes with boats on trailers. It is not as simple as CG of the boat. It also depends on how the boat is configured (Shoal draft or standard keel). What you have for an engine (inboard diesel or not), fuel aboard, water aboard, other equipment and location of their storage.
I would start with keel center a foot or more ahead of the trailer balance point (this may not be the middle axle). This might put the tongue weight a little heavy but you could balance that by moving gear (anchor and chain etc) moved or added to the cockpit.
Found this on the web about your boat.
http://www.canadianyachting.ca/lifestyle/yacht-clubs/1290-kelowna-yacht-club
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
The apparent center of gravity is back from where it really is when the trailer is at an angle on the ramp. We regularly watch the dolly wheel come off the ground as the trailer is on the crest of the ramp, and it's scary as all get out.
What you haven't said is what the tongue of the trailer is attached to when you are doing this. If it's loose, (and even if it isn't) you may assign a person to sit on the tongue while the trailer is on the ramp. We have found that as little as 100 lbs is the difference between the trailer being on the ground and wanting to free float.
Once it's out of the water, you can evaluate the loading position. Chances are that the boat will have to be set forward or aft a bit to balance things out, but there's no way you're ever going to tell that until it's on level ground, and quite probably on a weigh scale.
We've taken the numbers a bunch of times at the local scale and it's provided a bit of input to changing things up a tad.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
Cowpoke.
I would start with keel center a foot or more ahead of the trailer balance point (this may not be the middle axle).

Trailer balance point not the middle axle? Now that really complicates figuring out the correct loading position.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
T
What you haven't said is what the tongue of the trailer is attached to when you are doing this.

I have a 10' tongue extension attached to a one ton dually pickup.

Once it's out of the water, you can evaluate the loading position. Chances are that the boat will have to be set forward or aft a bit to balance things out, but there's no way you're ever going to tell that until it's on level ground, and quite probably on a weigh scale.

Level ground - good point. Thanks
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Cowpoke, I have a logistics background and we move cargo on trucks. We move the center of gravity on those 18 wheelers you see on the hwy all the time. Weight on those is based axle weight. moving the cg is done by moving cargo or moving the tongue cab location.
Yes is is a complication and requires you to exercise math/physics skills (oh gosh I wish I had stayed awake in High School).
You need to start with identifying the cg point of the unloaded trailer. That will help you decide where the cg point of the boat needs to be located. Match them up and you should be close to a neutral balance point with the boat on the trailer. Once I found that spot I would mark the location (paint on the trailer or a stick standing up so when you move the boat on to the trailer in the water you can find it). Then move the boat forward or shorten the tongue to adjust the weight on the tow ball. Extend the trailer tongue and you move the weight to the rear. Too much tongue weight and you ride with the dually front wheels in the air (difficult to steer around corners). Too little and the boat may raise the duallys' off the ground and you go no where, trying to drag the rudder.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Further to what John suggests, with a triple trailer, the balance point won't be obvious. We moved forward 4" based on what the scale told us, to get the tongue up a bit, and all it really did was double up the load on the front axle. In our case it was mostly to address the issues at the crest of the ramp, and it didn't do squat to address that. We need a couple of hundred pounds on the tongue itself when going over the crest.
So the suggestion stands, load it, put the football team on the tongue if need be, close your eyes if you have to :) and get the thing to a scale to determine where it needs to sit on the trailer.
Measure the total weight, measure the dolly wheel, measure the front axle, the back axle and use the total to determine the middle axle. It's a lot closer to accurate than you may think and it will give you the information to figure out where it needs to sit.
 
May 6, 2004
196
- - Potomac
I would just continue the trial and error method. The tongue weight should be about 10% of the combined boat/trailer weight for safe towing. Now, if you can find a bathroom scale that goes high enough...
 
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Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
I would just continue the trial and error method. The tongue weight should be about 10% of the combined boat/trailer weight for safe towing. Now, if you can find a bathroom scale that goes high enough...
Determining the tongue weight isn't nearly the challange as getting the boat back on the trailer each time. Keeping the keel centered while readjusting the jacks (underwater holding my breath) has proven quite the challenge. I think I'll try bolting on some 2 X 10's on each side of the trailer's center support that the keel rest on to help with this next time. Also this boat doesn't have a bow eye so moving the boat foward is done by completely floating the boat, lowering the jacks, then pulling while balancing myself on the trailer frame half submerged.
 
Aug 3, 2012
2,542
Performance Cruising Telstar 28 302 Watkins Glen
Forward edge of the bottom of the keel over the forward axle will do it.
Edit: I usually set my 272 with about 6 inches over the forward axle. Then you can change the angle with the drop of the hitch. I have 3 different boats, so I have 1 zero drop, one 4" drop and one 6" drop.
 
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Jun 8, 2004
10,024
-na -NA Anywhere USA
Cowpokee;

I noted you are located at Kerr Resivoir. One question before I go any further. Which one or lake is it. Is it the one that borders Virginia and North Carolina? Then I will comment from a dealer perspective with specific reference to that lake as I launched many large boats there.
 
Jun 4, 2004
88
- -First 310 -
Have you tried running the jib sheets forward to some attachment point either on the tow vehicle or the trailer and then using the winches to pull the boat onto the trailer.

It'll also keep the boat from sliding off the trailer when pulling out of the water.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
Cowpokee;

I noted you are located at Kerr Resivoir. One question before I go any further. Which one or lake is it.

Dave , we are in Oklahoma. I am trying to get the boat from a lake in Arkansas that doesn't have a lift of any kind.
 
Jan 8, 2015
360
MacGregor 26S, Goman Express 30 Kerr Reservoir
Have you tried running the jib sheets forward to some attachment point either on the tow vehicle or the trailer and then using the winches to pull the boat onto the trailer.

It'll also keep the boat from sliding off the trailer when pulling out of the water.
Very good idea Randy, why couldn't I have thought of that earlier.
At this point I am considering renting a truck crane to bring out and lift the boat onto the trailer. It will make adjusting the tongue weight much easier.
 

Kermit

.
Jul 31, 2010
5,657
AquaCat 12.5 17342 Wateree Lake, SC
If you have a friend or two who can look at this project objectively and, more important, with a calm, cool head you might have them come help. This could end up being fun and rewarding for all of you. And you might not need a crane.
 
Oct 24, 2010
2,405
Hunter 30 Everett, WA
Rereading your post, makes me look at it a bit differently. Are you complaining about the CG, or is it a problem of how the boat is attached to the trailer. You wrote "when we tried to pull forward, the tongue raised way up and the boat slid backwards; until it rested on the rudder." That tells me the transom wasn't properly supported and/or the boat wasn't secured to the trailer. When you pull forward, the high CG of a boat will try to rock it back. It will also try to slide back. That's normal. The boat must be secured to the trailer to remove it from the water. As someone said previously, the tongue weight must be checked on level ground. Even without an eye on the bow, you can run lines between cleats and the trailer (such as springlines between the rear cleats and the trailer tongue. Also add lines from the bow cleats to the tongue to keep the bow down.) Just make sure everything is secure before pulling it up the ramp.

Ken